1. Field of the Invention
This invention relates to a container for the storage and transport of explosives.
2. Description of the Related Art
The safe storage and transport of explosive materials is an ongoing problem which has resulted in many different proposed designs to either completely contain a detonation via a vessel capable of withstanding high pressures, or to ameliorate the effects of such a detonation by providing a vessel which will at least partially vent or absorb the pressures developed in such a detonation. As an example of the first type of design, Harvey U.S. Pat. No. 3,279,645 describes a flanged pressure vessel and a flanged cover which is bolted to the pressure vessel either through the respective flanges or through reinforcing rings positioned around the respective flanges.
Tabor U.S. Pat. No. 3,786,956 shows a container for explosives which is capable of at least partially absorbing a detonation by forming the walls of the container from a number of laminations. In addition, explosives placed within the container are spaced from contact with the outer walls of the container by a support structure which may comprise a net or non-fragmenting materials such as plastic foam or foam rubber, which act to further absorb shock waves generated by a detonation. Benedick et al. U.S. Pat. No. 4,055,247 also describes an explosion containment device capable of absorbing a detonation through the provision of an inner layer of distendable material which encloses the explosive, a continuous inner wall of steel surrounding the distendable material, a crushable layer around the continuous inner steel wall, and an outer steel wall.
Boyars et al. U.S. Pat. No. 4,432,285 describes a vessel for the storage of an explosive device comprising a bucket-shaped member having a wall structure formed of three metal layers with foamed plastic between the layers. A lid is formed of only foamed plastic so that the shock wave of any explosion will be directed toward the lid.
Poe et al. U.S. Pat. No. 4,347,929 describes a container for blasting caps which provides both absorption as well as pressure relief. The container comprises a cylindrical container with a screw-on door member that has corresponding buttress threads. The interior of the container is provided with an insert of a fragile foam or other absorptive material. The container also is provided with a vent mechanism comprising an opening through the wall of the container with a screw-in valve to permit gases produced during a detonation to escape at a low pressure.
Clark U.S. Pat. No. 2,917,927 discloses an explosion chamber which is provided with a relief valve which will open when the pressure in the chamber reaches a predetermined level.
MacQuilkin et al. U.S. Pat. No. 4,135,640 discloses a safety closure for a pressure vessel wherein a cover is bolted to the pressure vessel and a dome which fits over the cover shields the bolts. The dome has a bracket which engages a pressure relief valve to secure the dome over the bolts until the pressure relief valve has been opened so that the bolts cannot be accessed to open the cover until the pressure in the vessel has been vented.
Basterfield et al U.S. Pat. No. 4,411,372 discloses a pressure vessel with a cover having a groove formed therein to receive an 0-ring seal. The cover is secured to the vessel by hooks and bolts which permit the cover to move away from the container sufficiently to permit excess pressure to blow off when nuts on the bolts are slackened. However, the cover cannot be removed without rotating the cover with respect to the pressure vessel.
However, there still remains a need for a storage vessel for explosives wherein any detonation will be at least partially contained or absorbed, while the buildup of pressure is prevented by a pressure relief system wherein the extent and speed of the pressure relief is proportional to the pressure generated by the detonation.